Researchers set up a scenario where a dog watched his owner attempt to open a container while two actors were on set. In a series of three trials, one of the actors would help, respond neutrally, or refuse to help.

The other actor responded neutrally every time.

Afterwards, both actors would offer the dog a treat at the same time. In the trials where the actor who helped the owner or responded neutrally, the dog was equally likely to accept a treat from either actors.

However, in the scenario where the actor responded rudely, the dog was more likely to choose the neutral actor.

James Anderson, a comparative psychologist who worked on the study at Kyoto University said that dogs likely have a similar capacity to detect negativity as infants do.